Clean off the inner and outer bearing. There should be a series of numbers on there...something maybe like 624969. Take them to a bearing wholesaler or most local marine dealers even and match up the numbers. It's the easiest way to know you're getting exactly what you need.

i went ahead and pulled one of the hubs and they are 1-1/16. walmart sells them for about 12 bucks a set with seal. made in china of course. one thing i noticed that i havent seen before, the grease fitting is screwed into the end of the spindle with a passage thru the center to get grease to the inner bearing. that seems like a pretty good design.